The invention discloses a double slewing bearing. The double slewing bearing mainly comprises a base, two slewing support assemblies with the same structure which are symmetrically distributed at the two sides of the base, wherein the base is a square plate, fixed orifices are formed in the four angulus parietalis of the base, each slewing support assembly comprises two support plates with the same structure and a fixed block, the two support plates are welded vertically on the base and are parallel with each other, reamed holes with the same size are respectively arranged at the centers of the two support plates, a wear-resistant coating is coated in the reamed holes, the fixed blocks are welded between the two support plates, and are provided with mounting holes for mounting guide pins. According to the double slewing bearing disclosed by the invention, the strength requirement under a heavy load situation can be guaranteed, simultaneously, the soldering form is adopted, so that wholistic processing cost is lower, and the double slewing bearing can be used widely.